package Smbms.dao;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

public class BaseDao {
    private static String driver;
    private static String url;
    private static String username;
    private static String password;

    static {
        Properties properties = new Properties();

        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");

        try {
            properties.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
        driver = properties.getProperty("driver");
        url = properties.getProperty("url");
        username = properties.getProperty("username");
        password = properties.getProperty("password");

    }
    public static Connection getConnection() throws SQLException {

        Connection connection=null;
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(url,username,password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,PreparedStatement preparedStatement) throws SQLException {
        //预编译的sql在后面直接执行
        preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length; i++) {
            //占位符从1开始
            preparedStatement.setObject(i+1,params[i]);
        }
        resultSet = preparedStatement.executeQuery();
        return resultSet;
    }

    //编写增删改工具类
    public static  int execute(Connection connection,String sql,Object[] params,PreparedStatement preparedStatement) throws SQLException {
        preparedStatement = connection.prepareStatement(sql);

        for (int i = 0; i < params.length; i++) {
            //占位符从1开始
            preparedStatement.setObject(i+1,params[i]);
        }
        int update = preparedStatement.executeUpdate();
        return update;
    }

    //释放资源
    public static boolean closeResource(Connection connection,PreparedStatement preparedStatement, ResultSet resultSet){
        boolean flag = true;
        if(resultSet!=null){
            try {
                resultSet.close();
                resultSet = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false;
            }
        }
        if(connection!=null){
            try {
                connection.close();
                connection = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false;
            }
        }
        if(preparedStatement!=null){
            try {
                preparedStatement.close();
                preparedStatement = null;
            } catch (SQLException throwables) {
                throwables.printStackTrace();
                flag = false;
            }
        }
        return flag;
    }
}
